Modeling Antenna Feeds by Electric and Magnetic Current Sheets in Conjunction with the Method of Moments

Abstract:
The Method of Moment (MoM) approach is often employed when regarding free space antenna problems. However there are limitations concerning modeling certain antenna feeds. Dealing with semi-infinite structures (e.g. waveguide excitation) methods like FEM or FDTD are favorable due to the use of absorbing boundary conditions (ABC) or Perfectly Matched Layers (PML). In this paper a surface current excitations in connection with a MoM approach is introduced. A horn antenna as well as a biconical antenna are investigated for a single mode and a multimode excitation. The role of the termination of the feeding structure with regard to multiple reflections is exploited. A comparison with published theoretical results and measurements is given.